5,694 research outputs found
Mislocated fixations during reading and the inverted optimal viewing position effect
AbstractRefixation probability during reading is lowest near the word center, suggestive of an optimal viewing position (OVP). Counterintuitively, fixation durations are largest at the OVP, a result called the inverted optimal viewing position (IOVP) effect [Vitu, McConkie, Kerr, & O’Regan, (2001). Vision Research 41, 3513–3533]. Current models of eye-movement control in reading fail to reproduce the IOVP effect. We propose a simple mechanism for generating this effect based on error-correction of mislocated fixations due to saccadic errors. First, we propose an algorithm for estimating proportions of mislocated fixations from experimental data yielding a higher probability for mislocated fixations near word boundaries. Second, we assume that mislocated fixations trigger an immediate start of a new saccade program causing a decrease of associated durations. Thus, the IOVP effect could emerge as a result of a coupling between cognitive and oculomotor processes
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Digital/web-based technologies and purchasing and supply management: A UK Study
The digital revolution on the web/internet is believed to be having a major impact on the performance of firms’ purchasing and supply functions. Beyond anecdotal evidence however, little is known about the actual level of utilisation of web-based interaction technologies in purchasing and supply management (P&SM). This paper addresses this gap through an empirical survey of 156 UK-based organisations. Findings indicate that only six in every ten organisations use digital/web-based technology (DWBT) in P&SM, and that the usage level is particularly low in SMEs. Current uses, and the importance of DWBT in P&SM in the future are reported. The paper also investigates the perceived benefits of DWBT in this area, and the link between uses, benefits and P&SM relationship orientation. The evidence suggests that at present DWBT is not a key driver of closer (collaborative) buyer-supplier relationship development. Implications are put forward
Linear-scaling DFT+U with full local orbital optimization
We present an approach to the DFT+U method (Density Functional Theory +
Hubbard model) within which the computational effort for calculation of ground
state energies and forces scales linearly with system size. We employ a
formulation of the Hubbard model using nonorthogonal projector functions to
define the localized subspaces, and apply it to a local-orbital DFT method
including in situ orbital optimization. The resulting approach thus combines
linear-scaling and systematic variational convergence. We demonstrate the
scaling of the method by applying it to nickel oxide nano-clusters with sizes
exceeding 7,000 atoms.Comment: 10 pages, 4 figures. This version (v3) matches that accepted for
Physical Review B on 30th January 201
Eying the Body: The Impact of Classical Rules for Demeanor Credibility, Bias, and the Need to Blind Legal Decision Makers
This Article focuses on law students and attorneys, not parties, witnesses, experts, and others. Part I briefly provides background: the pivotal role of classical rhetoric in western education, including the United States, the dispositive position of demeanor credibility in oral trial, and the persistent doubts about its reliability—doubts turned into certainty over two decades of research. Part II compares modern and ancient manuals to explain the rules of elite demeanor and its ideological claim to truth. Part III compares ancient and modern understanding of popular delivery; that is, choices in non-verbal communication that run counter to the elite rules and demonstrate affiliation with non-elite groups as grounds for credibility. Part IV shows how elite rules are enforced in law schools and courts, limiting how advocates can speak and, thus, what can be communicated. Part V discusses the role of an assumed natural, common, bodily language in erasing the problem of actual differences and justifying the paradoxical claim that a jury can be manipulated by highly trained professionals, yet ferret out lies. Part VI discusses benefits of the common adoption of elite demeanor and suggests improved instruction at laws schools and screening decision makers in litigation to reduce the cost
PROFESSIONAL CHILDMINDING IN IRELAND: ECOCULTURAL PERSPECTIVES
The present study seeks to address the dearth of research focussed on childminding in Ireland, despite its significant role in national childcare provision. The overarching aims of this research are to interrogate the concept of professionalism and to explore the cultural models and praxis of childminders. The research has been conducted in an ecological theoretical framework: Ecocultural Theory (ECT) (Weisner 1993, 2002) predominantly, also referencing Bronfenbrenner’s Bio-Ecological Model (2006) and Attachment Theory. The history of childminding and current policy in Ireland, Europe and the USA are reviewed, including an overview of international research into childminding in the last 30 years. The study employed a mixed method approach including an online survey, and a World Café Forum initially before adapting the Ecocultural Family Interview for Childminders (EFICh), which included holistic ratings, photographs, field notes and a case study survey, to gain an in-depth picture of childminders’ practices. Findings show significant professionalisation among childminders and willingness to engage in a sensitive regulatory system, once aligned with childminders’ values and cultural models. In particular, two prevalent cultural models were identified: a Close Relationship model and a Real Life Learning model of pedagogy among childminders in the study. Any proposed national system of regulation, support, and education for childminders should be aligned with these cultural models if it is to prove meaningful, congruent and sustainable for childminders and parents, and maximise the benefits of childminding for children in the 21st century
The long-term effects of fire frequency and season on the woody vegetation in the Pretoriuskop Sourveld of The Kruger National Park
Student Number : 9008538J -
MSc Dissertation -
School of Biology -
Faculty of ScienceO’Regan SP, 2005. The long-term effects of fire frequency and season on the woody vegetation in the
Pretoriuskop sourveld of the Kruger National Park. MSc Dissertation, University of the Witwatersrand,
Johannesburg.
The role of fire in the management of conservation areas has historically been a contentious issue in which
traditional agricultural principles and ever-changing conservation principles tend to collide. The Kruger
National Park (KNP) in the early 1950s was no exception where the appropriate use of fire and its ecosystem
consequences were hotly debated. The controversy surrounding the management of fire in the KNP
highlighted the significant lack of understanding of fire and its role in the ecosystem and because of this
controversy, the Experimental Burn Plot (EBP) experiment was established in 1954. The EBP experiment
comprised 12 treatments, and a pseudo-randomised block design was used in which the 12 fire treatments
were replicated four times each in four of the six major vegetation zones identified at the time. The EBP
experiment originally comprised 192 experimental plots approximately 7 Ha in size each and covered
approximately 12 km2 in the KNP. The twelve fire treatments were an annual burn in August, biennial and
triennial burns in February, April, August, October, and December, and a control on which fire was excluded.
Despite having been plagued with negative assessments from internal and external researchers from its
inception, the EBP experiment was meticulously maintained, and it has now become a valuable research
asset in the KNP.
Four replicates of twelve plots each were located in the Pretoriuskop sourveld landscape of the KNP. These
replicates were named Fayi, Kambeni, Numbi, and Shabeni after nearby landmarks. The Pretoriuskop region
is a moist infertile mesic-savanna, which experiences on average 744mm of rain annually. The dominant tree
species in Pretoriuskop are Dichrostachys cinerea and Terminalia sericea and the dominant grass species is
Hyperthelia dissoluta. A baseline survey of the woody vegetation was done on all the Pretoriuskop plots in
1954 by HP Van Der Schijff. A second survey of the woody vegetation on all the Pretoriuskop plots was done
in 1996 by SP O’Regan. This provided a 42-year period of treatment application over which the effects of fire
frequency and season on the woody vegetation of the Pretoriuskop region were studied.
The aim of this study was to investigate the long-term effects of the twelve fire treatments on the density,
structure, and species composition of the woody vegetation in Pretoriuskop. The objectives of this study
were:
1. To carry out a complete re-survey of the trees and shrubs on the Pretoriuskop EBPs using similar
methods as those used in the baseline survey in 1954.
2. To capture into a digital format pertinent woody vegetation survey data from surveys that had been
conducted on the Pretoriuskop EBPs between 1954 and 1996.
3. To compare the density, structure, and composition of the woody vegetation on the Pretoriuskop
EBPs between 1954 and 1996, to determine the effects of fire on the woody vegetation of
Pretoriuskop.
4. To investigate the history of the Kruger National Park Experimental Burn Plots experiment.
The four replicates in the Pretoriuskop region were found generally to have very similar woody vegetation
traits (density, species composition, and structural composition). However, the EBPs were established and
surveyed in two distinct phases, the first phase comprised the control, August Annual, and the Biennial plots,
and the second phase comprised the Triennial plots. The baseline structural composition of the plots
established in the first phase was different from the structural composition of the plots in the second phase.
Furthermore, the Pretoriuskop EBPs are located in two distinct vegetation types, namely the open and the
closed Terminalia sericea \ Combretum woodlands of the Pretoriuskop region. The Numbi and Shabeni
replicates are in the open Terminalia sericea \ Combretum woodlands, and the Kambeni and Fayi replicates
are in the closed Terminalia sericea \ Combretum woodlands. It was found that the species composition of
the plots was influenced by the location of the plots in the different vegetation types.
The exclusion of fire in the Pretoriuskop sourveld results in an increase in the density of the overstorey and
understorey woody vegetation, and an increase in the number of species, species diversity, and species
evenness. This is because fire sensitive and fire intolerant woody species become more abundant as the
period between fires increases. In Pretoriuskop, there is no evidence of relay floristic succession, because
fire sensitive and fire intolerant woody species do not replace fire tolerant species. Instead, the floristic
succession is accumulative and fire tolerant, fire sensitive, and fire intolerant woody species coexist as the
period between fires increases. Woody species tolerant of frequent fires in Pretoriuskop are Albizia
versicolor, Catunaregam spinosa, Lonchocarpus capassa, Pavetta schumanniana, Senna petersiana,
Strychnos madagascariensis, and Turraea nilotica. Woody species that are sensitive or intolerant of fire in
Pretoriuskop are Acacia swazica, Bauhinia galpinii, Combretum mossambicense, Commiphora neglecta,
Croton gratissimus, Dalbergia melanoxylon, Diospyros lycioides, Diospyros whyteana, Euclea natalensis,
Hyperacanthus amoenus, Kraussia floribunda, Ochna natalitia, Olea europaea, Psydrax locuples,
Putterlickia pyracantha, Tarenna supra-axillaris, and Zanthoxylum capense. Dichrostachys cinerea and
Terminalia sericea were found to dominate in areas that had been burnt frequently as well as areas where
fire has been excluded. The change in the density of the woody vegetation as the inter-fire period increases
is not linear but rather J shaped with an initial decrease in the density as the inter-fire period increases from
1 year to 3 years. This initial decrease in density is the result of a loss of very short (<1m tall) woody
individuals. In contrast, there is no initial decrease in the number of tree equivalents (phytomass) of the
woody vegetation as the inter-fire period increases. After the initial decrease in the density of the woody
vegetation, the density increases as the inter-fire period increases beyond 3 years. Generally in
Pretoriuskop, post fire age of the vegetation was found to be an important factor affecting the structure of the
woody vegetation, and as the inter-fire period increases the number of structural groups, the structural
diversity, and the structural evenness of the woody vegetation increases. As the inter-fire period increases
the number of single-stem individuals relative to the number of multi-stem individuals increases, and the
average height of the woody vegetation increases. The findings regarding the effects of fire frequency on the
Pretoriuskop EBPs were similar to the findings on other fire experiments in mesic African savannas. The
finding on the Pretoriuskop EBPs differed from the findings in other fire trials that were in arid savannas in
Africa. Generally, the exclusion of fire in moist savannas (> 600 mm of rain annually) results in the woody
vegetation becoming denser, while the exclusion of fire in arid to semi-arid savannas (< 600mm of rain
annually) does not result in the woody vegetation becoming denser.
In Pretoriuskop, fires occurring in summer between December and February have a different impact on the
density, species composition, and structure of the woody vegetation than fires occurring in winter between
August and October. Furthermore, fires occurring in April have a different impact on the density, species
composition, and structure of the woody vegetation in Pretoriuskop. Woody vegetation burnt by summer fires
is denser than woody vegetation burnt by winter fires. The number of species and species diversity of the
woody vegetation is also higher in vegetation burnt by summer fires in comparison with vegetation burnt by
winter fires. The density and species composition of woody vegetation in areas that have been burnt in
summer fires is more similar to areas where fire has been excluded than to areas that have been burnt in
winter fires. The woody species associated with vegetation burnt in summer fires and where fire has been
excluded are Euclea natalensis, Antidesma venosum, Diospyros lycioides, Phyllanthus reticulatus, Grewia
flavescens, Grewia monticola, Ochna natalitia, Peltophorum africanum, Rhus pyroides, Diospyros
mespiliformis, Rhus transvaalensis, Securinega virosa, Putterlickia pyracantha, Rhus pentheri, Commiphora
neglecta, Heteropyxis natalensis, and Olea europaea. Structurally the average height of the woody
vegetation is taller in areas burnt by winter fires than in areas burnt by summer fires. The woody vegetation
in areas burnt in summer fires have more single-stem individuals relative to multi-stem individuals than in
areas burnt in winter fires. The structural composition of areas burnt in summer fires is more similar to areas where fire has been excluded than with areas burnt in winter fires. The structure of the woody vegetation in
areas burnt in winter fires is generally dominated by multi-stem individuals that are 0-1m tall or 3-5m tall. The
structure of the woody vegetation in areas burnt in summer fires or where fire has been excluded is
dominated by both single-stem and multi-stem individuals of all heights and basal diameters. Findings
regarding the effect of early dry season fires (April) in comparison with late dry season fire (August) on the
woody vegetation are consistent with the findings on other fire trails in Africa. However, a comparison of all
the fire-timing treatments between the Pretoriuskop and Satara EBPs in the KNP reveals that the timing of
fires affects the woody vegetation differently in different areas even when the affects at certain times appear
similar.
The data collected on the Pretoriuskop EBPs reveals that there have been significant changes in the woody
vegetation in Pretoriuskop between 1954 and 1996. The density of the woody vegetation increased between
1954 and 1996 by almost 200%. The number of species and the species diversity of the woody vegetation
also increased between 1954 and 1996. In 1954, there were approximately equal numbers of single-stem
and multi-stem individuals, while in 1996 there were more multi-stem individuals than single-stem individuals.
The increase in atmospheric CO2 levels between 1954 and 1996 is believed to have been a factor that has
driven the changes in the woody vegetation of Pretoriuskop between 1954 and 1996
The capitalist dialectics of international student mobility in the modern world-system
International higher education (IHE) and with that international student mobility (ISM) and internationalisation have become widely embedded in the educational mobility literature as commonplace conceptualisations in a world which is everywhere imagined as globalised. The present response paper considers the contribution of the papers of this special issue to our understanding of ISM and to international study-abroad in Asia while also locating this in the wider context of ISM in a capitalist modern world-system. The testimonies of the participants in these papers concerning their inter-Asian study-abroad experiences evidence their keen consciousness of the marketised nature of international higher education while also demonstrating how they negotiate and often resist this. The inter-Asian experience of international study-abroad while revealing of the racial and linguistic prejudices which some sojourners can face, also show how these international students may additionally discover accidental and unlooked for ‘fringe’ capitals which disrupt their ‘neoliberal’ positioning and are potentially transformative and self-liberating. In this brief response paper, I place ISM and inter-Asian study-abroad within a Marxist and critical realist dialectical ontology so as to be able to delve more deeply into this experience and to give greater theoretical context to the transformative possibilities which ISM presents
Fourth-order elliptic problems with critical nonlinearities by a sublinear perturbation
In this paper, we get the existence of two positive solutions for a fourth-order problem with Navier boundary condition. Our nonlinearity has a critical growth, and the method is a local minimum theorem obtained by Bonanno
Developmental Exposure of Rats to Chlorpyrifos Elicits Sex-Selective Hyperlipidemia and Hyperinsulinemia in Adulthood
Developmental exposure to chlorpyrifos alters cell signaling both in the brain and in peripheral tissues, affecting the responses to a variety of neurotransmitters and hormones. We administered 1 mg/kg/day chlorpyrifos to rats on postnatal days 1–4, a regimen below the threshold for systemic toxicity. When tested in adulthood, chlorpyrifos-exposed animals displayed elevations in plasma cholesterol and triglycerides, without underlying alterations in nonesterified free fatty acids and glycerol. This effect was restricted to males. Similarly, in the postprandial state, male rats showed hyperinsulinemia in the face of normal circulating glucose levels but demonstrated appropriate reduction of circulating insulin concentrations after fasting. These outcomes and sex selectivity resemble earlier findings at the cellular level, which identified hepatic hyperresponsiveness to gluconeogenic inputs from β-adrenoceptors or glucagon receptors. Our results thus indicate that apparently subtoxic neonatal chlorpyrifos exposure, devoid of effects on viability or growth but within the parameters of human fetal or neonatal exposures, produce a metabolic pattern for plasma lipids and insulin that resembles the major adult risk factors for atherosclerosis and type 2 diabetes mellitus
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